Sand blasting apparatus



H. BLFAY Er A1.

SAND BLAS-TING APPARATUS Ysept. 14, 1937.

" 2 sheets-Sheet 1 Filed March 4, 1935 f ORNEY Sept. 14, 1937. H. B. FAY Er Al.

SAND BLASTING APPARATUS Filed March 4, 1935 2 Sheets-Sheet 2 INVENTORS -/L/Orczce E y @mi BY(5x ESOW. Xgl/ inn ML v 9 a? ATTORNE' Y Patented sept. 14, 1937 UNITED Islxrrizs PATlzNT oFFlcaf i aoszLssz sANn nLAs'rlNG APPARATUS Home n. Fay, shakerneighu, mamma J.'

Quinn, ruedo, omo v Application mmh 4, 1935, sei-iai No. 9,884

lclaiml.

10 in construction, suiliciently light in weight to be 4 readily portable `and much `lower in operating cost than the air-operated sand blasting apparatus which is now'in general use.

To the accomplishment of the foregoingand related ends, said invention, then, consists of the steps rhereinafter fully described and particularly pointed out in the claims; the annexed drawings and the following description setting forth in detail certain structure embodying the 2o invention, such disclosed means constituting,

however, but one of -various mechanical forms in whichthe principle of the invention may be 'In said annexeddrawings:

A al Fig. 1 is a side elevation of our improved apparatus; 2 is a section on the line 2-2 in Fig. l; Fig. 3 is a plan view more or less diagrammatic in character of a modiilcation of the apparatus of Figs. l and 2; Fig. 3 is a vplan view I 30 of a modied type of wheel for use in our apparatus; Fig. 4 is a partial sectional view of a modification of -the"wheel; Fig. 5 is a partial edge viewof the wheel of Fig. 4; Fig. 6 is a partial side. elevation of another modication of the 35 wheelsyFig. 7 is a view partially diagrammatic showing another means for adjusting -the axial spacing' between the rolls; Fig. 8 is'a side elevation partially in section showing another method of. feeding abrasive to the rolls;.. Fig. 9 is a frag- QU mentary side elevation showing means for feeding the abrasive and the relationship between thel rolls; Fig. 10 iss plan view of the rolls showing in section the abrasive discharge nozzle; and

l1 is a side elevation partially in section of liliamodifiedwheelfY Y Sand blasting is an operation usually carried out by feeding abrasive. such as finely divided sand, shot or the like into a stream of compressed air and then directing the stream of air 50A and labrasive through avrestricted nozzle onto the surface to be treated. This method of cleaning is extremely eiIective, particularly in the rougheningand thoroughcleaning of surfaces of metal to which other metals are to be bonded,

55 the removal of pitted rust and scale and thecleaning of rough or irregular surfaces, such as stone or the like, but it has several serious objections, of which the foremost is probably the cost of theoperation; Air at high pressure has to be used and the compressing and storing of 5 air represents a very considerable expense.. while large volumes of air have to be usedv in any continued sand blasting operation. The upkeep of equipment is very considerable as the sand is carried at high speed and cuts away `the re- 10 stricted nozzles, which have to bereplaced at frequent intervals. A further objection is the volume of air which has to be handled after it leaves the nozzles and the scattering effect of this very large volume of air upon the abrasive,v as it carries the abrasive not only to the work` but away from it, scattering it in al1 directions and making it. advisable to operate in a closed room where the abrasive can be collected for salvage. If this is not done, the abrasive is wasted andthe cost ofthe operation is thereby additionally increased. In manufacturing operations where metal nishing is conducted after the cleaning or sand blasting operation,.sand

.blasting is particularly objectionablev as it nils g5 the air for long distances from the place ,of sand blasting with minute particles of abrasive which are detrimental to all types 'o f machinery with which they come in contact. A

The present apparatus is designed to provide V the same eil'ect as air sand blasting without the objectionable effects of scattering of the abrasive lof high upkeep and operating cost.

We have found that by supplying nely divided' abrasive, such as sand ,or shot, between two 35 rapidly moving members which are substantially in contact and which are provided with yieldablesurface elements. that 'the material is passed through the moving elements, discharged in substantially a sinne am; piane and given 40 a speed which is as high or which may be higher vthan .the speeds imparted to sand by air even under pressure up to 100 pounds. In additionV to these advantages the present apparatus is 4.adapted to handle larger. volumes of abrasive with a resulting increase in theV abrading action on the surface treated than is possible with airoperated apparatus. Referring now to Figs. 1' anclA 2. we have shown l a casing i, in which are mounted two movable im elements in the form of rotatable wheels 2 and 3, provided with 'yieldable surface coatings in the form of elastic bands l, which are preferably of relatively soft rubber molded or' bonded e 'Y jto the outer surface i of the wheels.: The casing 55 is provided with handles i and l for convenient manipulation by an operator and has the wheels disposed in parallelism and so mounted that they contact at the central plane I. Abrasive is applied to the wheels through any inlet conduit 9 mounted Vin the upper side of the casing I and terminating closely adjacent to the entering throat openings il between the two rotatable members.

Either one or both oi' the two rotatable members may be driven; but we have found it unhield by the yieldable surface elements on th'e necessary to drive both since the rotation of either wheel at high Vspeed slightly distends the elastic band I and this increase in the diameter of the band causes it to contact the band on the adjacent wheel even if the two wheels are not Valready in contact. In this way one wheel drives the other at'the same speed and we have found that a speed of between 9000 and 15000 surface feeta minute gives a very eifective cleaning ac-` tion, although it will be apparent that the speed power is required to operate the apparatus after the wheels have beenbrought up to speed and the power consumption compared to that oi' any air-operated apparatus is almost negligible in terinsofcost.- f 4. y'

The wheels 2 and 3 are shownin Fig. 2 as mounted upon shafts Il and Il respectively, each of which is mounted in anti-friction bearings I carrying cups Ii removably secured to the casing, and in the case ofthe wheel 2 the cup I6 is adjustably mounted along the median planeet the casing to permit of adjustment to compensate for wear on the surface of the bands. This attachment is secured by providing slots Ilv in the extending ears Il on the cups so that the entire cup may be shifted laterally and then xed in any desiredposition by means of the bolts I9.

`In Hg, 'l we have shown a modified means for adjusting the position'of onevof the two rolls, in which this means consists in formizig in the casingan opening 35, in which is slidably mounted e neming bleek. as, 1n which the shan-:1 ef i one of the two Awheels is journaled in suitable ball 3l. The bearingblock Itis urged toward the other of the two wheels, shown in' dotted line in the ligure, by means ot coil springs ee'p n; the pennen er which may be adjusted by meansofascrewll extending fromtherearot the member. in which is formed the slot 35.. Y

We have found that in order to impart to the abrasive substantially the full lineal speed of the wheels it is desirable to maintain the wheels in contact with each other under sumclent pressure toslightlv distort or flatten the contacting portions ,and I6 of the two wheels in the manner ShowninPlg. 9. Thematerialisthenfed from.

`the nozzle Il-into the entering throat opening between the wheels and is pomtively gripped and wheels,andwhendischargedfromthedlscharge throatopeningllithasbeengivensubstantially Vthe surface speed ofthe-wheels.

Itisalsoadvlsabletoprovidea discharge open-V ing or nozale'in the pipe Il of slightly shorter aces-sectionallengththanthewidthofthc interposed between the bearing'block and a.

aocaoea passed by means of a blower. From this conduit the air and abrasive is discharged into a cylindrical chamber 5I, from the bottom of which extends the pipe 52, which terminates in discharge nozzle III. The top of the chamber 5| f is open,.v but is closed by means of a line screen 53, which allows excess air to escape, carrying with it any ultra ilne material in the form of dust, while allowing the standard size particles of abrasive to pass downwardly through the pipe .52 and to the nozzle.

/ wheels shown in Figs. l and 2, this modiiication employing wheels 2l and 22, each of which is provided around its periphery with a pneumatic tire or tube 23 of substantially rectangular crosssection so that the planes of contact between the two tires will be flat and will operate in substantially the same manner as the bands on the wheels in Fig. 1.

In Figs. 4 and 5 there is shown another modication of the bands employed, in which the yielding bands Mare. providedwith a series of depressions or recesses 28 and this type of band may be used where it is desirable to project larger quantities of abrasive than can be readily passed between two flat connecting balnds of the type shown in Figs. 1 and 2. V

I n Fig. 6 there is shown still another modication ofthe rotatablel members or wheels ih which the rotating elements either by gravity or by other means. If the materialis fed by gravity, a

considerable head must be maintained on thematerial since we have found that there is aA slight back pressure or movement ofair in a direction opposite to that of the rotation of the wheels, which produces an' air ow up the conduit 9. This. counterilow is probably produced .by the eddy currents formed around the surfaces of the rotatable elements at the dischargethroat opening which produces a. slight vacuum at the center of the discharge throat opening, causing the air to be drawn toward this point and to then now-upwardly past the wheels and into the upper incoming air suilicient to balance the back pres` lsure in the conduit 52 of that gure.

The term "abrasive materia as employed herein, is intended to comprehend such material as sad, metallic grit and'metallic particlesof even fahly regular conformation, all of which may be .employed for the ,-prpose of cleaning, roughening o'r :smoothing 'a surface against which the material is projected by\ the present apparatus.

ther modes stated by any of the following claims or the equivalent of such stated means be employed. We therefore particularly point out and dis`- tinctly claim as our invention:-' 1. In apparatus of the character described, the combination of two parallel rolls, one provided with a compressible surface, and said rolls being mounted with their surfaces substantially in contact, means adapted to drive one of said rolls,

and means adapted to feed finely divided mate- Y rial to the entering throat opening between said rolls.

2. In apparatus of the character described, the vcombination of two parallel rolls mounted with their surfaces substantially in contact, and one of said rolls being adapted to yield slightly in the plane of the axes of saidv rolls to accommodate material passed between the same, Vand means adapted to feed finely divided material to the entering throat opening of said rolls along their line of surface contact.

3, In apparatus of the character described, the combination of two parallel rolls mounted with their surfaces substantially in contact, and one of said rolls having a compresslble surface member, means adapted to drive one of said rolls, means adapted'to feed finely divided material to the en. tering throat opening of said rolls. 40 4. In apparatus of the character described, the

combination of two parallel rolls mounted with their surfaces closely adjacent to each other, an extensible band on one of said wheels adapted uponrotation of said wheel at a predetermined 45 speed to extend and engage the other of said wheels in driving relation, means adapted to feed abrasive material to the entering throat opening of said rolls, and means adapted to rotate sai roll provided with said band.

D 5. In apparatus of the character described, the

combination of a casing, two rolls mounted therein in parallelism and having yielding bands encircling the same and in substantial contact, a conduit extending into said casing and tex'minat 55 ing adjacent the entering throat opening` of said rolls for feeding A abrasive thereto and meansadapted to drive one of said rolls.

6. In apparatus of the character described, the combination of a casing, a pair of rolls mounted in parallelism in said casing, yielding extensible bands secured to the peripheries of said rolls and with their surfaces in substantial contact, a conduit extending into said casing and terminating at a point close to the entering throat opening g between said rolls for feeding abrasive thereto, said casing completely enclosing said rolls but having a discharge opening opposite the exit throat opening of said rolls, and means for driving one of said rolls.

ofA applying the principle of our invention may be employed instead of 'the \one g explained, change being made as regardsthe; mechanism herein disclosed, provided the means\f` \w ith their surfaces in substantial contact, a conopening between said vrolls f or feeding abrasive thereto, said casing completely enclosing said rolls but Ahaving a discharge opening opposite the exit throat opening of said rolls, and a iiexibl'e shaft connected to Arotate one vof said rolls.

8. In apparatus of the character described, the combination of a casing, a pair of rolls mounted lin parallelism in said casing, yielding extensible bands secured tothe peripheries of said rolls and d iituextending into said casing and terminating at a" int close to the entering throat opening betweelisaid rolls for feeding abrasive thereto,

'said casing` \,-comp1et,ely enclosing said rolls but having va discharge opening opposite the exit throat opening of said rolls, means for driving one of said rolls, aniimmeans for adjusting said rolls axially with respect to each other to compensate for wear on sai`d` ands.

9. In apparatus of theeharacter described, the combination of two parallel rolls, each provided with a compressible surface, means forV driving one of saidrolls, meansgcadapted to feed finely divided materialV to the entering throat opening. between said rolls and means for maintaining, pressure upon said two rolls urging them toward each other.

l0. In -apparatus of the character described, the combination of a frame, two parallel rolls mounted in` said frame, each of said rolls being provided with a yieldable surface element secured thereto, means resiliently urging said rolls into contact, means for driving one of said rolls, and means adapted to feed finely divided material to the entering throat vopening between said rolls.

11. In apparatus of the character described, the combination of a frame, two parallel rolls mounted' therein, each of said rolls having `a compressible surface elementi secured thereto and said rolls having said surface element in sub- Vthe combination of a frame, two parallel rolls kmounted therein, each of said rolls having a compressible surface .element .secured thereto and 'said r'olls having said surface element in substantial contact, means for driving one of said `rolls, and means for blowing finely dividedmaterial at relatively slow speed and discharging the same to the entering throat between said rolls.

13. In apparatus of thecharacter described, the combination of a frame, two parallel rolls mounted therein,` said rolls having yieldable surface elements secured thereto and said surface elements being in substantial contact, means for supplying finely divided material uniformly Aacross the major portion of the entering throat opening between said rolls, and means for drivin/gj one of l said rolls.

l 14. In an apparatus of the character described, the combination of two parallel rolls. having contacting surfaces of yieldable material, means for said surfaces into increasing contact with each other, and means for feeding finely divided material between* said rolls at their point of initial contact.

15. In an apparatus of the character described.

Y 'the combination of movable members having op-` posed surfaces 1n contact over substantially their revolving said rolls at a velocity sufficient to urge l entire width and providing an area of contact substantiallyas'wide and long as said movable members are wide, means for moving said members in the same direction at their contacting portions, and means for introducing nely divided material between said surfaces at their point oi' initial contact.

16. In an apparatus of the character described, the combination of movable members having op' 10 posed surfaces in contact over substantially theiiL` y s entire width and providing an `area of contact substantially as wide and long as said movable members are wide, said members being composed of compressible material, means for moving said members in the same direction at their contactlng portions, and means for introducing finely divided material between said surfaces `at their point of initial contact.

l HORACE B. FAY.

NELSON J. QUINN.

I DISCLAIMER l2,092,962.-Horace B. Fay, Shaker Heights, and Nelson J. Quinn, Toledo, hio.v

SAND BLASTING APPARATUS.

Patent dated September 14, 19,37. filed March 14, 1939, by the patentees.

Disclaimer [Oficial Gazette April 18, 1939.]

entire width and providing an area of contact substantiallyas'wide and long as said movable members are wide, means for moving said members in the same direction at their contacting portions, and means for introducing nely divided material between said surfaces at their point oi' initial contact.

16. In an apparatus of the character described, the combination of movable members having op' 10 posed surfaces in contact over substantially theiiL` y s entire width and providing an `area of contact substantially as wide and long as said movable members are wide, said members being composed of compressible material, means for moving said members in the same direction at their contactlng portions, and means for introducing finely divided material between said surfaces `at their point of initial contact.

l HORACE B. FAY.

NELSON J. QUINN.

I DISCLAIMER l2,092,962.-Horace B. Fay, Shaker Heights, and Nelson J. Quinn, Toledo, hio.v

SAND BLASTING APPARATUS.

Patent dated September 14, 19,37. filed March 14, 1939, by the patentees.

Disclaimer [Oficial Gazette April 18, 1939.] 

